x.  -3a5u 


...THE... 


Function  oi  me  Laboratory 


SE60NDflRY  EDUCATION. 


An  Address  Delivered  at  Los  Angeles  Before  the  Science  Section  of 

the  Southern  California  Teachers'  Association, 

Dec.  21,  1900. 


S.  E.  COLEMAN,  S.  B.,  A.  M.  (harvard) 

Teacher  of  Physics  and  Astronomy  in  the  Los  Angeles 
High  School. 

Formerly  Teacher  of  Mathematics  in  the  Oakland 
.High  School. 


lOOO. 
K.   R.   Baumsirdt  *  Oo. 

LOS    ANOILI8,     C.AI-. 


THE  FUNCTION  OF  THE  LABORATORY  IN 
SECONDARY  EDUCATION. 

BY  S.   E.    COLEMAN. 

It  is  a  trite  saying  that  there  is  nothing  new  under  the  sun, 
and  though  it  has  been  disproved  again  and  again  during  the 
present  century  by  the  achievements  of  science,  yet  I  fear  that 
nothing  I  may  have  to  say  on  the  subject  of  science  will  in  any 
measure  serve  as  a  new  proof  of  the  falsity  of  the  proverb. 
However  that  may  be,  what  I  shall  present  to  you  is  largely 
the  result  of  my  own  experience,  both  as  a  teacher  and  as  a 
student  of  science;  and  whether  old  or  new,  true  or  false,  it 
represents  my  personal  convictions.  These  doubtless  will  be 
modified  by  further  experience;  but  such  as  they  are,  I  give 
them  to  you. 

Concerning  the  scope  of  the  subject  it  will  be  noted  that  it 
is  limited  to  secondary  education.  The  subject  of  nature  study 
in  the  grades  is  so  broad  and  is  at  the  present  time  arousing  so 
great  an  interest  that  it  has  this  year  been  assigned  to  a  sep- 
arate round  table;  and  anything  I  may  have  to  say  upon  that 
subject  will  be  merely  incidental.  Neither  shall  I  enter  upon 
a  discussion  of  the  several  functions  of  laboratory  work  in  col- 
leges, universities  and  technical  schools.  In  these  the  functions 
are  many  because  the  aims  are  many.  In  secondary  schools  the 
function  is  one  for  the  aim  is  one — education;  not  a  special 
or  technical  education  with  a  leaning  toward  this  or  that  "prac- 
tical" something-or-other,  but  a  symmetrical  unfolding  of  the 
latent  possibilities  of  the  mind. 

In  considering  the  means  by  which  the  science  courses  can 
best  contribute  toward  this  end,  it  is  important  to  recognize 
first  of  all  that  it  matters  less  what  is  taught  than  hozv  it  is 


323442 


4 
taught.  Any  one  of  the  sciences  of  the  high-school  course 
may  be  taught  in  such  a  way  that  its  educational  value  will 
be  insignificant,  and  any  one  of  them  may  be  taught  so  as  to 
produce  valuable  results.  I  do  not  mean  that  it  is  immaterial 
what  we  teach,  or  even  that  it  is  a  matter  of  little  importance. 
On  the  contrary,  I  believe  that  the  choice  of  material  for  the 
science  course  demands  greater  discrimination  than  for  any 
of  the  other  courses  of  the  high-school  curriculum ;  nevertheless 
scientific  education  does  not  mean  a  knowledge  of  this  or  that 
group  of  scientific  facts  so  much  as  it  does  an  attitude  of  the 
mind  toward  scientific  truth  in  general,  and  a  mental  discipline 
for  which  no  other  subjects  can  so  well  be  utilized.  But  these 
results  can  be  accomplished  only  by  right  methods  of  study.  If 
the  choice  of  material  for  the  science  course  is  difficult  it  is  not 
because  we  have  so  little  but  so  much  from  which  to  choose ;  and 
in  making  this  choice  the  chief  consideration  should  be  that  the 
material  chosen  shall  be  that  which,  under  the  existing  condi- 
tions, furnishes  the  best  opportunity  for  right  methods  of  study. 
What,  then,  are  right  methods  in  the  study  of  science  ?  Since 
we  can  really  know  only  that  which  we  have  experienced  or 
which  we  can  interpret  through  our  experience,  it  follows  that 
the  foundation  of  all  sound  instruction  in  science  must  be  a 
knowledge  of  things  and  of  phenomena  obtained  through  the 
senses,  and  not  a  second-hand  knowledge  about  them  obtained 
from  text  books  or  from  the  teacher.  Perhaps  you  regard  this 
as  so  nearly  axiomatic  that  it  is  unnecessary  to  dwell  upon  it 
or  even  to  state  it.  Yet  there  are  some  who  think  that  the 
requirements  of  nature  study  in  the  grades  are  met  by  the  use 
of  nature  readers;  as  if  every  need  of  the  budding  intellect 
could  be  met  by  words,  words,  words !  In  conversation  a  short 
time  since  with  the  special  teacher  of  nature  work  in  one  of 
the  northern  cities  of  the  state,  she  remarked  that  one  of  the 
greatest  difficulties  she  had  to  contend  with  was  that  the  grade 
teachers  told  their  pupils  the  things  that  they  should  find  out 
for  themselves.  She  would  leave  an  outline  of  work  which, 
if  properly  taught,  would  be  sufficient  for  a  month,  and  on  her 
next  visit  a  week  later,  the  teacher  would  say :  "Give  us  some- 
thing more  to  do ;  we  have  finished  what  you  gave  us  last  time.,, 


A  fine  example,  indeed,  of  the  "pouring  in'7  process ;  which  is 
based  upon  the  idea  that  the  acquisition  of  the  greatest  num- 
ber of  facts  in  the  least  possible  time  (through  the  exercise  of 
the  memory)  is  the  chief  consideration;  rather  than  the  devel- 
opment of  the  child's  powers  of  observation  and  expression. 
That  teaching  is  best  which  develops  in  the  child  the  greatest 
measure  of  self-reliance  and  the  greatest  power  of  independent 
effort.  The  value  of  a  teacher's  services  is  measured  less  by 
her  skill  in  telling  than  by  her  skill  in  leading  her  pupils  to 
find  out  for  themselves.  I  believe  that  the  education  of  today 
is  characterized  by  an  excessive  zeal  to  make  everything  as  easy 
as  possible  for  the  child,  and  that  this  zeal  defeats  its  own  pur- 
pose in  that  it  produces  minds  confirmed  in  the  habit  of  de- 
pendence and  having  little  capacity  for  spontaneous  activity. 

The  laboratory,  when  properly  utilized,  is  a  strong  cor- 
rective of  this  tendency.  I  do  not  mean  by  this  that  its  only 
function  is  that  of  an  antidote  for  certain  possible  or  actual 
evils  of  our  educational  methods.  Its  utility  has  a  far  more 
positive  basis,  which  is  but  emphasized  by  contrast  with  such 
evils.  In  the  laboratory  the  pupil's  task  is  to  find  out  something 
that  he  did  not  know  before,  and  to  get  it  by  the  direct  inter- 
rogation of  nature.  The  teacher  guides  and  directs,  but  it  is 
the  pupil  who  observes,  acts,  and  thinks.  The  amount  of  think- 
ing done  may,  of  course,  be  a  very  small  minimum ;  for  the 
work  may  be  done  in  a  perfunctory  and  mechanical  way.  Rut 
if  the  student  is  held  responsible  for  an  intelligent  interpreta- 
tion of  what  he  sees  and  does,  the  laboratory  work,  more  than 
anything  else,  will  tend  to  make  him  resourceful  and  self- 
reliant. 

The  science  courses  should  stand  in  close  relation  to  the 
every-day  experience  of  the  child ;  for  it  is  not  in  the  laboratory 
alone  nor  even  chiefly  that  he  comes  into  contact  with  things. 
When  he  enters  the  high  school  his  mind  is  already  stored  with 
a  large  and  miscellaneous  body  of  facts,  each  of  which  should 
ultimately  find  its  place  in  that  orderly  and  systematic  whole 
which  we  call  scientific  knowledge.  The  science  courses,  more 
especially  through  the  laboratory  work,  afford  the  means  of 
extending  and  systematizing  this,  as  yet,  unorganized  material. 


It  teaches  the  pupil  the  precise  laws  and  principles  stripped  of 
all  adventitious  and  confusing  phenomena.  This  leads  to 
definiteness  and  clearness  of  conception  such  as  cannot  be 
secured  in  any  other  way.  The  pupil  turns  from  the  experi- 
ment equipped  with  the  knowledge  by  means  of  which  he  can 
interpret  one  or  more  of  the,  to  him,  hitherto  hidden  mysteries 
of  nature.  For  example,  the  pupil,  in  the  physical  laboratory, 
studies  capillary  phenomena  by  means  of  a  glass  of  water  and 
a  set  of  small  glass  tubes.  Rightly  interpreted,  this  enables  him 
to  understand  how  a  lamp  wick  supplies  the  flame  with  oil, 
why  blotting-paper  must  be  porous,  why  a  pen  point  is  slit, 
and  why  the  occasional  cultivation  of  the  soil  in  summer  helps 
to  preserve  its  moisture.  The  laboratory  course  in  physics  will 
directly  or  indirectly  suggest  the  answers  to  such  questions  as : 
how  a  kite  is  sustained  in  the  air ;  why  a  handkerchief  cannot 
be  thrown  as  far  as  a  pebble;  why  a  vessel  without  a  cargo 
carries  a  ballast;  why  a  bicycle  rider  must  lean  inward  when 
riding  in  a  curve ;  why  a  hot  day  seems  hotter  and  a  cold  day 
colder  if  the  atmosphere  is  humid  than  if  it  is  dry ;  why  a 
carpet  seems  warmer  to  the  bare  feet  on  a  cold  morning  than 
the  bare  floor  does;  why  a  fall  of  the  barometer  indicates  the 
approach  of  a  storm;  etc. 

The  laboratory  work  should  be  further  supplemented  by 
systematic  outdoor  observation.  In  physical  geography  the 
pupil  should  be  encouraged  to  observe  the  points  of  sunrise  and 
sunset  at  different  seasons;  the  diurnal  motion  of  the  moon 
and  stars ;  and  the  annual  motion  of  the  stars.  He  should  de- 
termine the  altitude  of  the  sun  at  noon  at  different  seasons  by 
means  of  the  shadow  of  a  vertical  stick  (the  gnomon  of  the 
ancients)  ;  also  the  altitude  of  the  north  star  by  an  equally 
simple  method.  He  should  observe  local  examples  of  weather- 
ing and  erosion;  of  stratification;  and  of  tilting,  folding  and 
faulting  of  the  strata.  In  botany  and  zoology  the  pupil  should 
become  familiar  with  the  objects  of  his  study  not  only  in  the 
laboratory  but  also  in  the  field.  He  should  study  them  in  their 
relations  to  their  environment;  and  thus  by  his  own  observa- 
tions become  acquainted  with  the  salient  facts  of  their  life 
histories. 


Thus  the  facts  of  experience  already  acquired,  or  that  may 
be  acquired  during  the  high-school  period  by  systematic  use 
of  the  senses  during  out  of  school  hours,  furnish  the  material 
with  which  to  enrich  and  supplement  the  laboratory  course; 
while  the  latter  serves  the  no  less  important  purpose  of  pre- 
senting with  the  greatest  possible  simplicity  the  fundamental 
facts  and  principles  by  means  of  which  the  every-day  expe- 
rience is  interpreted  and  made  significant. 

An  important  question  in  all  science  teaching  is  the  use  to 
be  made  of  text  and  reference  books.  Only  by  observation  and 
experiment  can  a  sure  foundation  be  laid;  but  it  is  neither 
necessary  nor  desirable  to  limit  the  student  to  these  means  of 
instruction.  On  the  contrary  he  should  be  taught  to  make 
profitable  use  of  scientific  literature;  for  in  so  far  as  he  does 
so  he  becomes  heir  to  the  great  wealth  of  scientific  knowledge 
already  accumulated  by  the  labor  of  others.  The  danger,  how- 
ever, is  that  the  student  will  rely  too  much  upon  books  rather 
than  too  little ;  for  in  his  other  studies  he  has  learned  to 
regard  books  as  the  first  and  principal  source  of  information. 

But  the  use  to  be  made  of  books  will  be  mainly  determined 
not  by  the  pupil  for  himself  but  by  the  manner  in  which  the 
course  is  conducted;  and  in  this  regard  there  are  at  present 
in  vogue  two  widely  divergent  methods  of  procedure,  and  an 
intermediate  method  fairly  differentiated  from  the  other  two. 

In  one,  the  text  book  is  the  central  and  determining  element 
of  the  course;  the  experimental  part  is  incidental  and  subor- 
dinate. The  study  of  the  text,  especially  in  physics  and  chem- 
istry, is  usually  carried  well  in  advance  of  the  laboratory  work ; 
which  in  consequence  assumes  the  character  of  confirmatory 
evidence  of  what  has  already  been  learned  from  the  text  book 
and  from  the  experimental  illustration  accompanying  the  reci- 
tation. The  argument  for  this  method  is  admirably  stated  in 
the  preface  of  a  popular  text  book  of  physics,  from  which  I 
quote  the  following: 

"As  a  natural  reaction  from  the  old  regime,  in  which  the  teacher 
did  everything,  including  the  thinking,  came  the  method  of  original 
discovery;  the  text-book  was  discarded  and  the  pupil  was  set  to  redis- 
covering the  laws  of  physics.     Time  has  shown  the  'fallacy  of  such  a 


8 
method,  and  the  successful  teacher,  while  retaining  all  that  is  good 
in  the  new  method,  has  already  discovered  the  necessity  for  a  clearly 
formulated,  well  digested  statement  of  facts,  a  scientific  confession  of 
faith  in  which  the  learner  is  to  be  thoroughly  grounded  before  essaying 
to  explore  for  himself. 

"With  no  previous  instruction,  the  young  student  comes  to  the 
work  without  any  ideas  touching  what  he  is  expected  to  see,  with 
entire  ignorance  of  the  methods  of  experiment,  and  without  skill  in 
manipulation.  He  has  no  training  in  drawing  conclusions  from  his 
own  experiments.  He  is  not  a  skilled  investigator,  and  will  be  apt 
to  discover  little  beyond  his  own  ignorance,  a  result,  it  must  be  con- 
fessed, not  entirely  without  value.  Before  the  pupil  is  in  any  degree 
fit  to  investigate  a  subject  experimentally,  he  must  have  a  clearly 
defined  idea  of  what  he  is  doing,  an  outfit  of  principles  and  data  to 
guide  him,  and  a  good  degree  of  skill  in  conducting  an  investigation. 

"It  is  not  necessary  that  the  pupil  should  traverse  the  entire  sub- 
ject of  physics  before  taking  up  laboratory  practice,  but  he  shoud  be 
kept  in  his  class-work  well  ahead  of  the  subjects  forming  the  basis 
of  his  laboratory  experiments." 

In  the  opposite  method  the  laboratory  course  is  made  the 
central  and  controlling  feature  of  the  work ;  the  text  and  ref- 
erence books  are  supplementary.  The  method  is  based  upon 
the  idea  that  independence  and  self-reliance  in  observing  and 
in  drawing  inferences  from  what  is  observed  can  not  be  devel- 
oped if  the  student  always  undertakes  the  laboratory  work 
fortified  with  a  pre-judgment  of  what  he  is  to  see  and  what 
he  is  to  conclude.  An  admirable  text-book  of  physics  con- 
structed upon  this  plan  is  that  of  Hall  and  Bergen.  It  contains 
a  laboratory  course,  which  is  the  dominant  feature  of  the  book ; 
the  theory  being  developed  from  the  experiments.  Colton's 
Practical  Zoology,  which  is  a  laboratory  manual  only,  follows 
this  method.  I  quote  from  the  introduction  the  following  in 
regard  to  the  plan  of  the  book : 

"The  aim  is,  not  to  describe  for  the  student,  thus  robbing  him  of 
the  opportunity  to  develop  his  own  powers  of  description,  but  to 
name  the  parts,  telling  merely  enough  to  enable  him  to  recognize  and 
apply  the  names  to  them.  This  makes  a  real  connection  between  words 
and  things. 

"It  is  thought  best  for  the  student  to  make  many  of  the  definitions 
for  himself.  A  definition  thought  out  by  the  student  himself,  imper- 
fect though  it  be,  is  of  more  value  to  him  than  a  perfect  definition 


o 
learned  from  a  book,  which  often  appeals  to  mere  memory.     .     .     .     . 
It  develops  a  boy  more  to  earn  a  dime  than  to  receive  a  dollar  as  a 
gift. 

"If  the  main  object  of  this  study  is  the  mere  acquisition  of  facts, 
full  descriptions  of  most  animals  can  be  elsewhere  obtained ;  but  if 
the  more  important  part  in  education  is  to  lead  the  pupil  to  see  and 
think  for  himself,  then  some  such  method  as  this  should  be  used. 

"The  underlying  object  of  all  our  teaching  is  to  make  seeing, 
thinking,  self-reliant,  honest  men  and  women.  All  branches  of  natural 
science,  rightly  pursued,  are  powerful  means  to  this  end.     .     .     . 

"Do  not  set  out  with  the  intention  of  finishing  this  book  in  a  given 
time;  zoology  is  the  study  of  animals;  study  animals  as  long  as  the 
time  allows,  trying  to  learn  as  much  as  possible  from  a  few  typical 
forms ;  this  will  give  a  better  view  of  the  animal  kingdom  than  reading 
many  books  concerning  many  animals." 

To  summarize :  By  the  first  method  the  order  of  procedure 
with  a  topic  is  (i)  study  of  the  text-book,  (2)  recitation,  fre- 
quently with  experimental  illustration  by  the  teacher,  (3)  the 
laboratory  work.  By  the  second  method  it  is  ( 1 )  the  laboratory 
work,  (2)  study  of  the  text-book  and  references,  (3)  recitation 
and  discusison,  first  with  reference  to  the  interpretation  of  the 
experiments,  then  to  their  application  as  suggested  by  the 
pupils'  reading.  The  latter  will  be  illustrated  by  experiments 
performed  by  the  teacher  as  occasion  requires,  but  not  to  the 
same  extent  as  in  the  preceding  method. 

The  intermediate  method  makes  the  laboratory  work  more 
nearly  co-ordinate  with  the  other  part  of  the  course.  In 
physics,  according  to  this  plan,  the  order  would,  in  general, 
be  somewhat  as  follows :  ( 1 )  qualitative  class-room  experi- 
ments by  the  teacher,  presenting  fundamental  phenomena,  for 
example,  refraction  and  the  formation  of  images,  the  corres- 
ponding part  of  the  text  being  assigned  for  reading  and  dis- 
cussion; (2)  the  laboratory  work,  developing  mainly  quanti- 
tative relations ;  for  example,  the  index  of  refraction  of  glass 
and  of  water,  the  focal  length  of  a  lens,  and  the  study  of  con- 
jugate foci;  (3)  a  discussion  of  the  experiments,  together  with 
any  further  application  of  the  laws  developed  from  them. 

The  relative  value  of  these  three  methods  remains  to  be 
considered.  It  is  to  be  expected  that  there  will  be  considerable 
difference  of  individual  opinion  on  this  point,  and  to  a  certain 


IO 

extent  this  is  admissible ;  for  the  individuality  of  the  teacher 
necessarily  plays  an  important  part  in  determining  what  is 
best  for  him.  Nevertheless,  if  the  principles  I  have  endeavored 
to  set  forth  are  true,  the  first  method  must  be  unqualifiedly  con- 
demned. The  difference  between  the  other  two  is  much  less  im- 
portant ;  yet  it  seems  to  me  the  preference  is  decidedly  in  favor 
of  the  second.  In  answer  to  an  objection  quoted  above,  it  may 
be  said  that  this  does  not  mean  that  the  pupil  is  to  be  turned 
loose  in  the  laboratory  to  rediscover  the  laws  of  physics  or  of 
any  other  science  by  the  method  of  original  discovery.  The 
original  investigator  is  first  of  all  a  person  of  rare  intellectual 
endowments ;  in  the  second  place  he  is  guided  in  his  researches 
by  a  knowledge  of  all  that  his  predecessors  have  discovered  in 
his  chosen  field  of  investigation.  Since  the  young  student 
rarely  has  the  first  and  never  the  second  of  these  qualifications, 
it  is  necessary  to  provide  him  with  substitutes  therefor.  These 
are  the  laboratory  manual  and  the  teacher.  The  objection  above 
quoted  continues :  "Before  a  pupil  is  in  any  degree  fit  to  inves- 
tigate a  subject  experimentally,  he  must  have  a  clearly  defined 
idea  of  what  he  is  doing,  an  outfit  of  principles  and  data  to 
guide  him,  and  a  good  degree  of  skill  in  conducting  an  investi- 
gation." It  seems  pertinent  to  ask  how  a  person  can  acquire 
"a  good  degree  of  skill  in  conducting  an  investigation"  before 
he  has  begun  to  investigate.  It  is  very  much  like  advising  one 
not  to  go  near  the  water  until  he  has  learned  how  to  swim. 
Since  the  one  idea  is  no  less  absurd  than  the  other,  a  formal 
answer  to  the  objection  is  unnecessary. 

We  have  so  far  given  attention  almost  exclusively  to  the 
kind  of  discipline  the  laboratory  should  afford  and  the  best 
methods  of  securing  it.  It  remains  to  consider  very  briefly 
the  availability  of  the  several  sciences  as  means  to  this  end; 
with  reference  particularly  to  the  special  function  of  each  and 
the  order  in  which  they  should  be  pursued. 

As  I  have  already  said,  we  are  not  at  a  loss  for  material. 
In  the  report  of  the  Committee  of  Ten  of  the  National  Educa- 
tional Association  the  following  sciences  are  considered  avail- 
able for  high  schools :  physical  geography,  botany,  zoology, 
physiology,  chemistry,  physics,  astronomy,  geology,  and  mete- 


II 


orology ;  affording  in  all  enough  material  for  a  daily  lesson  in 
science  for  eight  years  without  going  beyond  the  scope  of 
existing  high-school  text-books. 

The  subjects  chosen  for  the  high-school  course  from  this 
or  any  other  list  should  be  those  that  are  of  the  greatest  value 
as  information  and  as  a  means  of  mental  discipline.  Their 
disciplinary  value  must  be  judged  by  the  principles  already  set 
forth.  What  shall  be  the  test  of  their  value  as  information? 
In  the  first  place,  I  am  pleased  to  admit  that  the  "practical" 
value,  in  the  utilitarian  sense,  of  the  information  to  be  obtained 
from  any  one  of  these  subjects,  so  far  as  it  can  be  taught  in 
the  high  school,  is  so  small  that  it  is  not  worth  consideration. 
And  I  will  add  that  the  practical  value,  in  this  sense,  of  any 
subject  is  the  least  of  all  the  considerations  that  should  deter- 
mine its  right  to  a  place  in  the  school  curriculum.  It  should 
be  understood  that  I  am  not  here  speaking  of  technical  and  pro- 
fessional schools,  whose  value  no  one  will  deny,  and  whose 
advantages  should  be  accessible  to  all  who  desire  them;  but 
of  the  public  schools  through  which  all  must  pass  in  order  to 
secure  a  liberal  education.  The  value  of  the  elementary  science 
courses  as  information  lies  in  this :  they  interpret  to  the  student 
his  material  environment  and  its  phenomena.  A  person  with- 
out this  knowledge  is  like  Alice  in  Wonderland,  who  sees  so 
many  inexplicable  things  no  less  wonderful  than  the  grinning 
Cheshire  cat,  which  had  a  habit  of  vanishing  slowly,  "beginning 
with  the  end  of  the  tail  and  ending  with  the  grin,  which  re- 
mained some  time  after  the  rest  of  it  had  gone,"  that  she 
finally  ceases  to  expect  any  reasonableness  in  such  a  mad 
world;  and  among  her  later  adventures  holds  a  conversation 
with  the  weeping  mock-turtle,  without  any  consciousness  of 
the  strangeness  of  the  situation.  You  smile  at  the  absurdity 
of  such  conceits,  yet  the  literature  for  "grown-ups"  contains 
absurdities  no  less  impossible,  which  are  narrated  as  plausible 
happenings.  Probably  the  majority  of  the  readers  of  "King 
Solomon's  Mines''  have  not  considered  it  at  all  remarkable 
that  "the  full  bow  of  the  crescent  moon"  should  appear  above 
the  eastern  horizon  shortly  after  sunset,  "filling  the  earth  with 
a  faint  refulgence" ;  that  on  the  following  night  the  full  moon 


12 

should  rise  "in  splendor"  at  about  ten  o'clock;  and  that  the 
next  day  there  should  be  an  eclipse  of  the  sun  "causing  total 
darkness  for  half  an  hour  or  more." 

Those  subjects  or  topics  are  most  valuable  as  information 
which  treat  of  the  most  conspicuous  or  most  habitual  elements 
of  our  physical  environment.  They  are  also  well  adapted  to 
the  requirements  of  an  introductory  course  in  science,  because 
they  are  already  more  or  less  familiar.  The  early  work  in 
science  should  be  an  interpretation  and  systematization  of  facts 
already  familiar,  rather  than  the  acquisition  of  new  facts. 
Such  a  course  will  most  surely  awaken  in  the  child  an  interest 
in  science,  because  it  affords  a  ready  insight  into  its  meaning 
and  methods.  The  course  which  most  nearly  fulfills  these 
requirements,  is  physical  geography,  which  is  defined  in  the 
report  of  the  Committee  of  Ten  as  the  study  of  "the  physical 
environment  of  man."  Those  familiar  with  recent  text-books 
on  this  subject  know  the  wide  range  of  facts  and  phenomena 
which  they  comprehend.  The  things  which  lie  nearest  at 
hand  in  our  every-day  life  are  here  considered,  whether  they 
belong  to  the  sciences  of  physics,  chemistry,  botany,  zoology, 
astronomy,  geology,  mineralogy,  or  meteorology.  Valuable 
results  will  be  obtained  from  the  study  and  discussion  of  a  good 
text-book  on  the  subject,  if  supplemented  by  systematic  out- 
door observation  and  field  work  as  already  suggested.  But 
some  experimental  illustration  in  the  class-room  is  almost 
indispensable,  and  much  is  desirable.  In  addition  to  all  this 
there  should  be  a  very  elementary  laboratory  course  to  accom- 
pany the  study  of  the  text,  and  no  school  that  is  without  it 
should  be  regarded  as  having  reached  a  satisfactory  standard 
of  efficiency  in  this  subject. 

After  this  general  introductory  course,  the  more  special- 
ized courses  properly  follow.  But  in  what  order?  For  an 
answer  I  cannot  do  better  than  to  quote  from  the  report  of 
the  subcommittee  on  zoology  to  the  Committee  on  College  En- 
trance Requirements  of  the  National  Educational  Association 
(1899).     The  report  says: 

Studies    on    living    things    appeal    more    strongly    to    students    of 
fifteen  than  to  those  of  seventeen  years  of  age,  whereas  the  reverse  is 


13 

true  of  precise  formal  argument.  The  power  of  exact  reasoning  can- 
not be  said  to  develop  early,  and  the  less  formal  methods  of  biological 
science  are  also  transitional  to  those  of  physics  and  chemistry.  Fur- 
thermore, the  mathematical  training  necessary  for  physics  particularly 
is  not  obtained  by  the  pupil,  under  present  programs  in  secondary 
schools,  early  enough  to  allow  the  introduction  of  work  in  physics 
before  the  third  year  of  the  secondary  course ;  hence  your  sub-com- 
mittee is  all  but  unanimous  in  recommending  that,  since  work  in 
zoology  does  not  require  the  rigid  training  necessary  for  more  formal 
work  in  physics  and  chemistry,  it  should  precede  work  in  these 
branches.  It  should,  however,  be  preceded,  in  its  opinion,  by  a  year 
in  general   science   and  physiography. 

"Whether  illustrated  by  the  study  of  plants  or  animals,  the  phe- 
nomena of  life  are  so  similar  and  so  clearly  complementary  that  a 
rational  arrangement  of  courses  calls  for  study  of  botany  and  zoology 
in  successive  terms  or  years.  Various  circumstances  may  determine 
in  the  individual  case  the  order  to  be  followed,  yet  neither  should  be 
studied  at  the  expense  of  the  other,  but  both  receive  a  due  share  of 
attention." 

Among  the  biological  sciences  botany,  zoology  and  physi- 
ology are  all  available ;  but  since  at  the  most  there  is  not  time 
for  more  than  two,  it  is  important  to  consider  which  are  the 
most  valuable  for  the  purposes  of  secondary  education.  In 
this  connection  it  is  significant  that  in  the  report  of  the  Com- 
mittee on  College  Entrance  Requirements  physiology  is  not 
even  mentioned,  and  also  that  it  is  not  in  the  list  of  subjects 
preparatory  to  our  state  university.  The  conference  on  nat- 
ural history  in  its  report  to  the  Committee  of  Ten,  says : 

"While  physiology  is  one  of  the  biological  sciences,  k  should  be 
clearly  recognized  that  it  is  not,  like  botany,  and  zoology  a  science  of 
observation  and  description;  but  rather,  like  physics  or  chemistry,  a 
science  of  experiment.  While  the  amount  of  experimental  instruction 
(not  involving  vivi-section  or  experiment  otherwise  unsuitable)  that 
may  with  propriety  be  given  in  the  high  school  is  neither  small  nor 
unimportant,  the  limitations  to  such  experimental  teaching,  both  as  to 
kind  and  as  to  amount,  are  plainly  indicated.  For  this  reason  the 
study  of  physiology  as  a  component  of  the  high-school  course  should 
be  regarded  as  of  importance  rather  as  an  informational  than  as  a 
disciplinary  subject,  and  should  be  taught  largely  with  reference  to 
its  practical  relations  to  personal  and  public  hygiene." 

These  statements  apply  with  still  greater  force  to  the  teach- 
ing of  physiology  in  the  lower  grades;  and  if  the  subject  is 


continued,  as  it  sometimes  is,  through  the  eight  years  of  the 
primary  and  grammar  school  course,  with  unending  reitera- 
tions upon  such  topics  as  bones,  joints,  tobacco,  nervous  sys- 
tem, stomach,  heart,  alcohol  and  the  stomach,  liver,  food  and 
stimulants,  opium,  digestive  organs,  narcotics,  kidneys,  mus- 
cles and  alcohol,  tobacco,  opium,  bones,  and  so  on  ad  nauseam  ; 
and  if  in  addition  to  all  this,  a  course  in  physiology  is  pre- 
scribed in  the  high  school,  the  subject,  in  my  opinion,  is  re- 
ceiving an  amount  of  attention  out  of  all  proportion  to  its 
relative  importance,  either  as  an  informational  or  as  a  dis- 
ciplinary subject.  In  the  lower  grades  it  is  of  necessity  almost 
entirely  an  informational  subject,  taught  upon  authority  and 
appealing  to  the  memory  only.  For  this  reason,  the  report 
on  physiology  quoted  above  recommends  that  in  these  grades 
the  subject  be  limited  to  "simple  and  practical  instruction  upon 
the  subject  of  personal  health  and  its  care."  "Such  instruc- 
tion," the  report  continues,  "should  rather  be  given  and  re- 
ceived (as  many  other  things  concerning  conduct  must  be 
received  by  young  children)  upon  authority,  than  as  an  appeal 
to  the  judgment  of  the  pupil  as  based  on  his  physiological 
knowledge." 

With  the  facilities  afforded  by  a  properly  equipped  biological 
laboratory,  a  course  in  physiology  in  the  high  school  may  be 
given  that  will  have  an  important  disciplinary  value.  The 
laboratory  work  will  be  partly  experimental,  but  mainly  ob- 
servational, consisting  for  the  most  part  of  dissections  of  the 
lower  animals,  including  some  microscopical  study  of  the  vari- 
ous tissues.  But  as  the  experimental  work  deals  mainly  with 
fermentation,  and  with  the  chemistry  of  foods  and  of  the 
digestive  processes,  and  as  these  subjects  can  not  be  ade- 
quately presented  without  a  considerable  knowledge  of  chem- 
istry on  the  part  of  the  pupil,  they  would  better  be  given  as 
a  part  of  the  course  in  that  subject.  Moreover,  since  the  dis- 
sections and  other  observational  work  of  the  laboratory  course 
in  physiology  are  in  reality  studies  in  comparative  anatomy 
and  physiology,  it  would  be  much  more  valuable  if  amplified 
and  given  as  a  laboratory  course  in  zoology.     The  reading  and 


15 

recitations  accompanying  such  a  course  may  include  all  that 
the  pupil  needs  to  know  of  human  anatomy  and  physiology. 

It  will  be  assumed  without  further  argument  that  botany 
and  zoology-  should  be  given  a  place  in  the  high  school  curric- 
ulum, following  a  course  of  one  or  two  terms  in  physical 
geography  and  general  science.  It  is  not  my  purpose  to  dis- 
cuss the  character  of  these  courses  further  than  to  protest 
against  the  excessive  use  of  the  compound  microscope.  Some 
knowledge  of  vegetable  and  animal  histology  is  necessary, 
but  it  is  more  important  that  the  pupil  should  be  trained 
in  the  observation  and  in  the  knowledge  of  things  as  they 
appear  to  the  unaided  vision  than  as  seen  through  an  ex- 
pensive instrument,  which  few  will  ever  possess  and  which 
none  carry  habitually  with  them.  With  a  compound  micro- 
scope before  his  eye  the  pupil  is  looking  at  the  thin  edge 
of  his  subject  in  more  senses  than  one.  In  a  recent  conversa- 
tion on  this  subject,  a  teacher  of  biology  told  me  that  a  young 
graduate  of  one  of  our  universities  had  shown  her,  with  great 
pride,  a  set  of  beautiful  botanical  microscope  slides  that  she 
had  prepared  in  her  laboratory  course  at  college.  The  teacher 
admired  them,  admitting-  that  they  exhibited  greater  skill  in 
such  work  than  she  herself  possessed,  and  finally  asked  the 
young  lady  what  she  had  learned  from  them.  "Why,"  was 
the  answer,  "I — I  really  don't  know."  On  the  use  of  the 
microscope  the  committee  on  botany  reports  as  follows  to  the 
Committee  on    College   Entrance   Requirements : 

"In  the  judgment  of  your  committee  the  compound  microscope  is 
both  useful  and  necessary  in  the  demonstration  of  many  important 
structures  that  should  be  brought  to  the  attention  of  secondary-school 
students,  but  its  excessive  use  in  the  first  contact  with  plants  is  to  be 
deplored.  The  compound  microscope  is  a  difficult  piece  of  apparatus 
for  a  young  student  to  use  intelligently,  a  proper  interpretation  of  that 
which  is  seen  demanding  considerable  training,  involving  more  total 
time  and  longer  periods  than  are  given  in  secondary  schools.  Another 
danger  of  such  a  course  is  that  the  contact  with  plants  is  one  of 
structure  rather  than  of  function,  and  details  of  minute  struct  ure  are 
not  related  to  previous  or  subsequent  experience,  except  in  the  case 
of  very  few  secondary-school  pupils;  besides,  it  involves  a  needlessly 
extensive  and   difficult    terminology  at   the  first   contact." 


i6 

The  committee  on  zoology,  in  its  report  to  the  same  body, 
expresses  a  similar  opinion. 

As  already  stated,  the  biological  sciences  are  largely  obser- 
vational and  descriptive,  and  hence  are  well  adapted  to  the 
early  part  of  the  high  school  course.  On  the  other  hand, 
the  physical  sciences,  more  especially  physics  and  chemistry, 
treat  more  of  phenomena  than  of  things,  and  are  mainly  experi- 
mental. They  therefore  appeal  more  to  the  reasoning  facul- 
ties, and  are  best  adapted  to  the  later  years  of  the  course.  The 
logical  aspect  of  the  work  is,  however,  pre-eminently  character- 
istic of  physics.  The  predominant  questions  in  biology  are 
What?  and  How?  In  physics  it  is  Why?  Elementary  chem- 
istry occupies  a  middle  position  in  this  respect.  Like  the  bio- 
logical sciences,  it  is  largely  concerned  with  the  observation 
and  description  of  facts ;  while  the  inferences  drawn  are  for 
the  most  part  simple  and  immediate,  the  reasoning  involved 
being  of  a  very  elementary  character.  Elementary  chemistry 
can  be  little  else  than  the  empirical  study  of  the  chemical  prop- 
erties of  the  common  elements  and  their  familiar  compounds. 
The  laws  and  theories  of  chemistry  can  be  utilized  only  to  a 
limited  extent  in  giving  the  elementary  presentation  of  the 
subject  a  rational  basis.  Elementary  physics,  on  the  contrary, 
consists  almost  entirely  in  the  experimental  study  of  the  sim- 
pler physical  laws  and  principles,  and  their  application  in  ex- 
plaining familiar  phenomena.  It  is,  in  short,  a  practical  course 
in  inductive  and  deductive  logic. 

It  follows  from  the  foregoing  that  physics  is  a  much  more 
exacting  study  than  chemistry,  and  requires  for  its  successful 
prosecution  a  greater  maturity  of  intellect.  Hence  the  proper 
order  for  these  subjects  is  chemistry  before  physics.  There 
is  another  important  reason  for  this  order  in  schools  where  the 
same  amount  of  time  is  devoted  to  each ;  namely,  the  fact 
that  physics  is  the  broader  subject,  treating  of  a  much  greater 
variety  of  things  and  phenomena  that  form  an  important  part 
of  man's  physical  environment.  Tt  therefore  comprehends  a 
much  greater  amount  of  available  material,  and  should  be 
eiven  either  more  time  than  chemistrv  or  the  advantage  of 


17 

the  increased  capacity  for  work  that  would  result  from  the 
prior  study  of  chemistry.  The  superior  claim  of  physics  is 
commonly  recognized  in  the  schools  of  the  Eastern  States. 
In  Cambridge,  Mass.,  for  example,  a  laboratory  course  of 
twenty  experiments  in  mechanics  and  light  is  given  in  the 
ninth  year;  in  addition  to  which,  in  the  English  High  School, 
physics  is  taken  daily  during  the  eleventh  year  and  chemistry 
only  three  times  per  week  during  the  twelfth  year;  while 
in  the  Latin  High  School  physics  is  taken  daily  during  the 
twelfth  year  and  every  other  day  during  the  thirteenth  year, 
and  chemistry  is  not  taken  at  all. 

Wishing  to  know  how  the  students  viewed  these  questions, 
I  recently  submitted  the  following  list  of  questions,  without 
comment,  to  pupils  in  the  Los  Angeles  High  School,  who 
have  had  physics  and  who  are  now  taking  the  second  term  of 
chemistry. 

1.  Do  you  regard  chemistry  or  physics  the  more  difficult? 
Give  reasons. 

2.  Which  subject  presents  the  greater  experimental  dif- 
ficulties?    Is  there  much  difference  in  this  respect? 

3.  How  do  the  subjects  compare  in  the  task  they  impose 
upon  the  memory? 

4.  How  do  they  compare  in  the  task  they  impose  upon  the 
reason  and  understanding? 

5.  Which  subject  do  you  think  should  be  taken  first? 
Why? 

I  received  answers  from  thirty-two  students  as  follows : 


Physics. 

1.  More  difficult   16 

2.  Greater  experimental  difficulties.  .      16 

3.  Greater  task  for  the  memory. ...       4 

4.  Greater  task  for  the  reason 28 

5.  Which  should  be  studied  first.  ...     11 


Chem- 

No dif- 

istry. 

ference. 

13 

3 

3 

13 

27 

1 

1 

3 

16 

5 

i8 

An  analysis  of  the  answers  to  the  first  and  fifth  questions 
gave  the  following  results : 

No.  of 
answers. 
Physics  is  more  difficult  because : 

It  requires  more  reasoning n 

There  are  many  laws  and  principles ...  3 

It  requires  more  memorizing 1 

It  is  less  interesting 1 

Total    16 

Physics  is  easier  because! 

"You  can  reason  things  out  better" ....  3 

Chemistry  is  more  difficult  because: 

There  is  more  memory  work 6 

The   experimental   work  is  more   diffi- 
cult   1 

It  covers  more  ground 1 

It  is  more  abstract 1 

(No  reason  given) 1 

Total    10 

Physics  should  come  first  because : 

It    "lays    the    foundation    of    science," 
"teaches  the  fundamental  ideas  of 

science,"   etc 3 

It  develops  the  power  of  reasoning.  ...  2 
There  is  more  time  for  the  harder  study 

in  the  third  year 2 

It  is  an  aid  in  the  study  of  chemistry.  .  2 

It  requires  more  independent  work.  ...  1 

It  is  more  interesting 1 

It  is  easier 1 

Total   12 


19 
Chemistry  should  come  first  because: 

It  is  an  aid  in  the  study  of  physics 6 

Memorizing  is  easier  than  reasoning-.  .  .       4 
It  would  prepare  for  the  more  difficult 

reasoning  in  physics 2 

It  is  easier 3 

It  teaches  the  distinction  between  chem- 
ical and  physical  properties I 

(No  reason  given) 1 

Total    17 

These  answers  are  in  striking  agreement  with  what  has 
already  been  said  on  the  subject,  and  as  that  discussion  was 
written  before  the  questions  were  presented  to  the  pupils,  the 
answers  are  to  be  regarded  as  confirmatory  evidence.  Two 
of  the  answers  to  the  fifth  question  are  very  aptly  stated.  "I 
think,"  says  one,  "that  chemistry  should  be  taken  first  be- 
cause your  reasoning  power  increases  more  in  the  extra  year 
than  your  memory  would.  Therefore  by  taking  physics  last 
you  have  the  advantage  of  the  extra  year  in  reasoning  power.'' 
Another  says,  "I  think  that  chemistry  should  be  taken  first. 
It  is  more  of  a  tax  on  the  memory,  and  by  developing  the  rea- 
soning power  to  some  extent,  prepares  the  way  for  more  care- 
ful reasoning  in  physics  later.  Memory  is  better  developed 
than  reasoning  power  in  most  of  us." 

Concerning  the  subject-matter  of  the  course  in  chemistry, 
it  will  be  remembered  that  in  discussing  physiology  I  spoke 
of  the  advantage  of  making  the  study  of  fermentation  and  the 
chemistry  of  foods  and  of  the  digestive  processes  a  part  of 
the  chemistry  course.  Such  work  as  this  cannot  be  satisfac- 
torily done  earlier,  and  it  is  much  more  important  than  any 
attempt  at  a  systematic  treatment  of  qualitative  analysis.  The 
latter  can  not  in  an  elementary  course  be  made  to  yield  either 
valuable  information  or  discipline,  while  the  topics  suggested 
afford  both.  The  testing  of  substances,  including  ores  and 
minerals, — and  there  should  be  a  considerable  amount  of  such. 


20 

work, — should  not  be  with  the  aid  of  analytical  tables,  which 
encourage  mechanical  work;  but  by  outlines  suggesting  suit- 
able dry-  and  wet-way  experiments  which  will  compel  the 
pupil  to  think,  and  will  afford  an  interesting  and  useful  re- 
view of  the  properties  of  the  substances  tested. 

On  the  subject  of  physics  little  need  be  added  here.  One 
point,  however,  I  wish  to  emphasize,  and  it  is  of  sufficient  im- 
portance to  stand  thus  alone.  It  is  that  the  quantitative  lab- 
oratory experiment  must  be  regarded  not  as  a  proof  of  the 
law,  but  as  a  proof  of  the  pupil.  The  pupil  should  be  led  to 
realize  something  of  the  extent  and  accuracy  of  the  experi- 
mental evidence  in  favor  of  the  laws  and  principles  of  physics ; 
and  this  can  be  accomplished  in  no  better  way  than  by  teaching 
him  to  recognize  the  principal  sources  of  error  in  his  own 
work  and  to  estimate  their  probable  magnitude.  He  must  be 
taught  that  his  experiments  are  crude,  and  serve  to  illustrate 
or  to  suggest  rather  than  to  verify  the  laws  of  physics.  In 
every  case  where  possible,  the  pupil  should  compute  the  per 
cent,  of  error  of  his  result  by  comparing  it  with  the  theoretical 
value ;  and  if  the  discrepancy  is  greater  than  a  reasonable 
maximum,  he  should  be  required  to  repeat  the  experiment. 
If  this  plan  is  followed  from  the  first,  the  pupil  will  be  rapidly 
trained  to  do  thoughtful  and  painstaking  work.  I  speak  from 
experience. 

There  is  but  little  time  in  the  high  school  for  scientific 
courses  in  addition  to  those  already  considered,  and  certainly 
no  more  than  these  should  be  prescribed.  But  in  large  high 
schools  it  is  customary  to  offer  certain  elective  studies  in  the 
senior  year,  and  of  these  I  think  at  least  one  should  be  a 
scientific  course.  Among  those  available  are  astronomy,  geol- 
ogy, mineralogy  and  an  advanced  course  in  physics.  The  last 
should  be  largely  experimental,  and  should  not  be  undertaken 
without  a  much  better  laboratory  equipment  than  most  schools 
possess. 

The  other  subjects  provide  abundant  material  for  half-year 
courses  in  astronomy,  astronomy  and  geology,  or  geology  and 
mineralogy.     Mineralogy   must   be   treated   experimentally   if 


21 

at  all.  Astronomy  and  geology  afford  opportunity  for  much 
interesting  and  profitable  observation ;  but  they  are  mainly 
informational,  subjects.  And  this  information  should  be  the 
possession  of  every  well  educated  person.  I  venture  to  say 
there  are  few  things  that  will  exert  a  more  wholesome  and 
elevating  influence  upon  the  youthful  mind  than  the  study  and 
contemplation  of  the  order  and  harmony  of  the  universe 
through  all  space  and  all  time.  Our  joys  and  sorrows  are 
things  of  a  day;  and  even  the  momentous  questions  that  in- 
volve the  welfare  of  nations  soon  cease  to  engage  the  thoughts 
of  men ;  but  there  is  that  which  endures,  in  the  contempla- 
tion of  which  "ancient  as  the  hills"  seems  to  refer  to  but  yes- 
terday, and  space  "world  wide"  shrinks  to  microscopic  insig- 
nificance before  the  extended  vision.  And  through  it  all  is 
order  and  system  and  harmony, — a  cosmos,  not  a  chaos.  Such 
themes  will  leave  an  impress  of  no  mean  value  upon  character. 
The  disciplinary  value  of  astronomy  is  by  no  means  inconsid- 
erable, for  it  furnishes  many  and  varied  applications  of  the  laws 
of  physics. 

In  conclusion:  Studies  are  valuable  as  information  or  as 
a  means  of  discipline  or  both  in  varying  proportions.  From 
the  point  of  view  of  the  secondary  school,  scientific  studies  are 
valuable  as  information  in  so  far  as  they  impart  an  orderly 
and  rational  view  of  that  which  is  most  significant  in  man's 
physical  environment.  They  have  disciplinary  value  in  so 
far  as  they  train  the  powers  of  observation,  description,  com- 
parison, reason,  and  judgment;  and  this  comes  mainly,  though 
not  wholly,  from  the  laboratory  work.  It  is  hardly  necessary 
to  say  that  this  training  will  be  of  inestimable  value  outside  the 
field  in  which  it  has  been  acquired  and  throughout  life.  In 
all  the  complexities  of  human  affairs,  whether  social,  business, 
or  political,  such  training  will  help  its  possessor  to  see  clearly, 
reason  correctly,  and  act  wisely. 

Finally,  in  his  personal  and  intimate  contact  with  nature 
under  many  and  varied  conditions,  the  student  will  come  to 
realize  that  in  nature  trickery,  deceit,  evasion,  and  partiality 
have  no  part;  her  ways  are  trustworthy,  impartial,  reason- 


22 

able;  her  laws  immutable,  and  the  penalty  for  their  infringe- 
ment inexorable;  and  granting  that  such  things  are  not  the 
best  means  of  developing  a  noble  character,  nevertheless  they 
can  scarcely  fail  to  foster  a  love  of  truth,  honesty,  temperance, 
and  justice,  without  which  no  character  can  be  noble. 


Reprinted  from  School  Science  and  Mathematics,  Vol.  11,  1911 

Pages  816-826. 


THE  PURPOSE  AND  METHOD  OF  EXPERIMENTAL  WORK  IN 

PHYSICS.1 

By  S.  E.  Coleman,  B.S.,  M.A., 

Head  of  the  Science  Department  and  Teacher  of  Physics  in  the 

Oakland  High  School,  Oakland,  Cal. 

The  Laboratory  Course. 

Diverse  and  conflicting  views  have  been  entertained  with  re- 
spect to  the  proper  function  of  the  laboratory  course  in  elementary 
physics.  At  the  one  extreme  it  has  held  a  subordinate  position 
as  a  loosely  attached  appendage  to  the  text-book  course;  and, 
in  the  manner  of  appendages,  it  trailed  humbly  behind  the  work 
of  the  class  room.  At  the  other  extreme  it  has  been  the  dominant 
feature  of  the  physics  course,  and  as  such  has  claimed  much 
the  greater  part  of  the  time  allotted  to  the  subject.  It  has  been 
wholly  qualitative,  wholly  quantitative,  and  partly  both.  It  has 
been  made  the  basis  of  inductive  teaching,  both  good  and  bad; 
and  it  has  flippantly  undertaken  to  "verify"  the  generalizations 
of  experts  in  experimental  science. 

The  experiment  of  teaching  experimental  physics  has  been 
tried  out  along  all  possible  lines;  and  the  good  and  the  bad,  the 
better  and  the  worse,  have  been  evaluated  with  some  approxima- 
tion to  accuracy.     Differences  of  opinion  still  exist;  but  they 


^Excerpt  from  "The  Physics  Teachers'  Handbook,"  a  forthcoming  work  by  the 
writer,  read  before  the  Pacific  Coast  Association  of  Chemistry  and  Physics  Teachers,  July 
29, 1911. 


EXPERIMENTAL  WORK  IN  PHYSICS  817 

relate,  for  the  most  part,  to  questions  of  minor  importance.  The 
proper  field  of  laboratory  physics,  its  aims,  and  its  methods, 
can  now  be  discussed  with  some  possibility  of  fairly  representing 
a  majority  opinion. 

The  laboratory  work  should  constitute  an  organic  and  integral 
part  of  the  physics  course,  and  should  be  pursued  concurrently 
with  the  instruction  of  the  class  room  throughout  the  subject. 
Its  specific  purpose  is  to  enlarge  the  pupil's  acquaintance  with 
the  facts  of  the  subject  at  first  hand.  This  purpose  is  shared 
on  an  equal  footing  with  the  experiments  of  the  class  room, 
performed  by  the  teacher.  The  experimental  facilities  of  the 
class  room  and  the  laboratory  are  different  and  mutually  comple- 
mentary.   Neither  can  take  the  place  of  the  other. 

The  relative  amount  of  lecture  table  and  laboratory  experi- 
ments may  vary  considerably  without  detriment  to  the  subject, 
for  there  is  much  common  ground  that  may  be  covered  by  either 
or  both  together ;  but  a  well-balanced  development  of  both  is 
necessary  for  the  best  results.  The  exclusive  allotment  of  qualita- 
tive experiments  to  the  class  room  and  of  quantitative  to  the 
laboratory  is  an  unwise  and  unnecessary  restriction  of  the  field 
of  usefulness  of  each.  As  a  general  rule,  the  quantitative  work 
belongs  to  the  laboratory  course ;  but  roughly  quantitative  experi- 
ments are  often  valuable  in  the  class  room,  as  a  basis  for  the 
preliminary  discussion  of  quantitative  laws ;  and,  where  occasion 
demands,  they  may  be  made  to  serve  in  the  place  of  laboratory 
experiments.  The  special  field  of  the  lecture  table  experiment 
is  in  the  qualitative  study  of  phenomena  which  can  be  readily 
observed  at  a  distance.  By  the  use  of  the  projection  lantern 
this  field  can  be  extended  to  include  phenomena  which  would 
otherwise  require  minute  observation  at  close  range.  In  such 
cases,  however,  as  well  as  in  others  which  cannot  be  thus  adapted, 
the  laboratory  offers  the  best  opportunity  for  effective  work.  In 
the  laboratory  the  pupil  feels  the  increasing  pressure  as  he  pushes 
a  light  body  (as  a  beaker)  further  down  in  water;  he  feels  that 
a  copper  rod  becomes  hot  enough  to  burn  his  fingers  while  a 
glass  rod  remains  cold  when  an  end  of  each  is  held  in  a  flame ; 
he  sees  that  an  object  at  the  bottom  of  a  vessel  appears  to  rise 
:as  water  poured  in.  Qualitative  experiments  such  as  these, 
and  there  are  many  of  them,  yield  an  experience  which  is  differ- 
ent in  kind  and  in  value  from  that  gathered  in  observing  lecture 
table  demonstrations  at  a  distance;  and  on  this  score  they  are 
■entitled  to  a  place  in  the  laboratory  course. 


818  SCHOOL  SCIENCE  AND  MATHEMATICS 

As  to  the  general  character  of  the  laboratory  work,  every  ex- 
periment should  measure  up  to  two  requirements.  It  should 
be  real  physics,  and  it  should  have  a  definite  purpose  and  value 
as  a  part  of  the  course.  It  is  a  waste  of  valuable  time  to  spend 
the  first  days  in  the  laboratory  on  pure  measurement  with  vernier 
and  micrometer  calipers,  the  diagonal  scale,  the  spherometer,  etc., 
with  no  physics  in  sight.  It  is  the  specific  purpose  of  the  labora- 
tory work  to  teach  physics ;  and  the  experimental  procedure 
should  be  as  simple  and  direct  as  will  serve  the  purpose.  It  is 
an  educational  blunder,  as  well  as  a  waste  of  time,  to  introduce 
the  use  of  micrometric  instruments  and  the  Jolly  balance  in 
the  work  on  density  and  specific  gravity,  when  the  pupil  has  had 
no  practice  in  the  simpler  methods  of  measuring  and  weighing. 

The  educational  value  of  the  laboratory  work  depends  very 
largely  upon  the  mental  attitude  which  the  pupil  is  led  to  assume 
toward  it.  Above  all  things  else  it  should  bear  the  stamp  of 
sincerity.  There  should  be  no  playing  at  discovery;  and  of 
real  discovery  there  is  none,  forAdoes  fij)  not  consist  in  following 
a  blazed  trail^  There  should  be  no  shallow  pretense  of  "veri- 
fying" the  general  laws  and  principles  of  physics.  The  attitude 
of  verification  stultifies  the  intelligence ;  for  it  ignores  both  the 
quality  and  the  quantity  of  the  experimental  evidence  upon  which 
the  generalizations  of  science  are  founded,  and  it  attaches  a 
wholly  fictitious  value  to  the  practice  work  of  the  student.  The 
laboratory  experiment  is  not  a  proof  of  the  law,  but  an  aid  to 
the  right  understanding  of  it.  This  distinction  is  fundamental. 
For  example,  in  the  study  of  Boyle's  law  the  pupil  experiments 
with  one  gas  only  (air),  at  one  temperature  only,  and  with  only 
a  moderate  range  of  pressure.  With  the  apparatus  commonly 
provided,  the  work  is  well  done  if  it  is  not  in  error  by  more 
than  one  or  two  per  cent.  If  this  is  accepted  as  an  exemplifica- 
tion of  the  law,  with  a  fair  and  reasonable  approximation  to 
accuracy,  it  is  well.  If  it  is  further  understood  that  the  law  has 
been  established  by  similar  but  much  more  accurate  work  with 
many  gases,  for  a  much  greater  range  of  pressures,  and  at 
different  temperatures,  and  that  the  law  has  thus  been  found 
to  be  only  a  close  approximation  to  the  truth,  and  that  it  fails 
even  as  an  approximation  for  any  gas  when  near  a  temperature 
and  pressure  at  which  it  liquifies,  it  is  well.  Such  teaching. will 
foster  a  just  appreciation  of  what  science  is,  and  a  very  whole- 
some and  serviceable  respect  for  scientific  authority.  But  if 
the  pupil  is  led  to  believe  that  all  this,  or  any  part  of  it,  may  be 


EXPERIMENTAL  WORK  IN  PHYSICS  819 

assumed  on  the  basis  of  his  experiment,  the  work  is  a  harmful 
perversion  of  scientific  education. 

It  is  of  course  true  that  the  laboratory  work  affords  a  sufficient 
basis  for  important*  inferences  and  conclusions ;  but  these  are 
necessarily  simple,  and  generally  narrow  and  partial.  Intellectual 
integrity  demands  that  they  go  no  further  than  the  experimental 
•data  will  warrant. 

The  most  important  and  perhaps  the  most  difficult  problem 
concerning  the  laboratory  work  is  to  make  effective  use  of  it. 
If  it  has  only  such  connection  with  the  work  of  the  class  room 
.-as  the  pupil  makes  on  his  own  initiative,  it  will  have  very  little 
value  indeed.  Pupils  well  above  the  average  in  intelligence  and 
steadiness  of  purpose  generally  fail  to  grasp  the  full  significance 
of  an  experiment  until  the  results  have  been  subjected  to  a 
searching  analysis  under  the  guidance  of  the  teacher;  and  the  less 
capable  members  of  the  class  are  hopelessly  incapable  of  deriving 
reasonable  benefit  from  the  work  without  this  assistance.  Ac- 
ceptable results,  duly  recorded  in  a  notebook,  give  no  assur- 
ance of  successful  work.  It  is  the  interpretation  and  assimi- 
lation of  results  that  counts,  and  that  only. 

The  means  by  which  this  result  can  best  be  secured  depend 
largely  upon  the  size  of  the  class,  the  time  allotted  to  the  labora- 
tory work,  and  the  predilections  of  the  teacher.  With  a  class  of 
ten  or  less,  individual  instruction  in  the  laboratory  may  suffice,  es- 
pecially with  a  double  laboratory  period.  With  only  a  single 
period  for  the  work  and  large  classes  (fifteen  to  twenty-five),  this 
becomes  impossible.  Under  such  conditions  the  only  effective  plan 
is  to  make  the  laboratory  experiment  the  basis  of  a  class  discus- 
sion, after  all  members  of  the  class  have  performed  it.  This  class 
discussion  or  recitation  should  fit  in  with  the  text-book  lesson 
on  the  topic  which  the  experiment  illustrates.  On  this  plan,  the 
laboratory  work  precedes  the  formal  recitation.  It  is  an  obvious 
•advantage  to  bring  the  two  as  close  together  in  time  as  possible ; 
and  this  is  the  principal  reason  for  providing  several  sets  of 
-apparatus  for  each  experiment,  as  discussed  later. 

As  a  further  means  of  shortening  the  time  interval  between 
•  the  work  of  the  laboratory  and  the  class  room,  the  school  program 
should  be  arranged,  if  possible,  so  that  the  laboratory  days  may 
be  varied  at  will.  Thus  it  may  be  found  desirable  to  run  three 
days  of  recitation,  two  of  laboratory  work,  four  of  recitation,  one 
of  laboratory  work,  two  of  recitation,  etc.,  according  as  the  lab- 
oratory experiments  may  chance  to  fit  in  with  the  work  of  the 


820  SCHOOL  SCIENCE  AND  MATHEMATICS 

class  room.  The  loss  of  the  movable  laboratory  day  is  one  of  the 
great  disadvantages  of  the  double  laboratory  period,  which,  as  a 
rule,  must  come  on  fixed  days  of  the  week. 

In  order  to  make  the  most  out  of  the  laboratory  work,  it 
must  be  brought  into  mutually  helpful  relation  with  the  study  of 
the  text-book ;  each  must  be  serviceable  as  a  means  of  interpreting 
the  other.  The  text  and  the  experiments  are  different  lines  of 
approach  to  the  same  goal,  namely,  an  understanding  of  physics. 
The  two  aids  to  the  understanding  will  be  most  effective  when 
used  together.  This  leads  to  the  practical  rule  that  at  least  one 
reading  of  the  text-book  on  the  topic  of  the  experiment  should 
precede  the  laboratory  hour ;  that  the  text-book  should  be  brought 
to  the  laboratory,  to  be  used  at  the  pupil's  pleasure  and  upon  the 
advice  of  the  teacher;  and  that  the  lesson  of  the  experiment 
should  be  borne  in  mind  as  the  text  is  further  studied  in  prepara- 
tion for  the  recitation. 

I  am  not  in  sympathy  with  the  view  that  the  pupil  should 
come  to  the  laboratory  wholly  uninformed  on  the  subject  of  his 
experiment,  in  order  that  he  may  weakly  imitate  the  methods 
and  weakly  experience  the  pleasures  of  original  discovery.  True, 
the  laboratory  should  afford  valuable  training  in  scientific  methods 
and  habits  of  thought,  and  nothing  that  militates  against  this 
should  be  tolerated ;  but  the  use  of  the  text-book  as  recommended 
is  not  open  to  such  objection.  It  should  be  remembered  that 
the  scientific  investigator,  in  addition  to  his  other  qualifications, 
is  skilled  in  the  use  of  books.  Before  undertaking  original  work 
on  any  problem,  he  consults  authorities  to  find  out  what  is 
already  known  about  it.  To  save  time  and  useless  labor,  he 
begins  his  own  investigations  where  his  predecessors  left  off. 
The  boy  of  to-day  who  is  interested  in  wireless  telegraphy  or 
in  aviation  has  learned  this  lesson  without  any  help  from  his 
teachers ;  for  he  is  a  diligent  reader  of  scientific  periodicals  which 
give  up-to-date  information  on  his  hobby.  Training  in  the  ef- 
fective use  of  scientific  literature  is  no  less  a  necessary  part 
of  scientific  education  than  is  training  in  the  methods  of  investiga- 
tion; and  the  former  is  more  likely  to  be  of  use  to  ninety-nine 
out  of  a  hundred  pupils  than  the  latter. 

The  principal  factors  which  determine  the  details  of  laboratory 
management  are  the  length  of  the  laboratory  period,  the  size  of 
the  classes,  the  number  of  sets  of  apparatus  available  for  each  ex- 
periment, and  the  number  of  pupils  (one  or  more)  assigned  to 
each  set. 


EXPERIMENTAL  WORK  IN  PHYSICS  821 

The  one  important  advantage  of  the  double  laboratory  period 
(an  hour  and  a  half)  is  that  it  affords  time  for  the  experimental 
work  of  the  exercise  and  for  the  preparation  of  a  complete  and 
final  report  upon  it.  With  the  judicious  help  of  the  teacher  at 
the  time  of  the  writing,  the  errors  of  the  record  are  reduced  to 
a  minimum ;  and,  under  the  rule  that  notebooks  are  not  to  be 
taken  from  the  laboratory,  the  record  is  free  from  the  suspicion 
of  dishonesty  which  too  often  attaches  to  work  done  on  the  out- 
side. The  double  laboratory  period  usually  carries  with  it  the 
disadvantage  of  fixed  laboratory  days,  the  objection  to  which  has 
already  been  noted ;  and  each  class  takes  a  larger  fraction  of 
the  teacher's  time.  With  a  single  laboratory  period,  it  is  practi- 
cally necessary  to  have  the  record  completed  on  the  outside; 
since  it  is  out  of  the  question  to  limit  the  course  of  experiments 
to  such  as  can  be  performed  and  written  up  in  so  short  a  time. 
The  only  serious  objection  to  this  plan  is  that  it  puts  temptation 
in  the  way  of  pupils  who  have  access  to  old  notebooks  on  the 
same  experiments.  This  evil  may  be  reduced  to  a  negligible 
minimum,  or  it  may  become  a  serious  menace  to  the  morals  of 
the  class.  It  all  depends  on  the  teacher's  ability  to  manage  the 
situation.  If  it  is  clearly  understood  that  the  pupil's  promotion 
will  be  determined  by  the  physics  stored  in  his  head  rather  than 
in  his  notebook,  and  that  the  notebook  is  only  a  means  to  an 
end,  not  an  end  in  itself,  the  temptation  to  dishonesty  will  not  be 
very  serious. 

The  proper  size  of  laboratory  classes  has  been  the  subject  of 
much  discussion.  The  view  entertained  by  many  that  the  number 
should  not  exceed  fifteen,  and  would  better  be  ten  or  twelve, 
appears  to  me  untenable.  If  the  instruction  based  on  the  labora- 
tory work  is  given  only  as  individual  instruction  in  the  laboratory ; 
if,  in  other  words,  the  pupil's  laboratory  experience  is  not  corre- 
lated in  the  class  room  with  the  work  of  the  class  room,  then 
indeed  a  laboratory  section  of  ten  or  twelve  is  the  maximum  for 
satisfactory  results.  But  why  conduct  the  work  on  such  a  plan? 
It  is  appallingly  wasteful  of  the  teacher's  time  and  energy  to 
discuss  in  full  detail  the  significance  of  each  experiment  with 
the  pupils  individually,  and  it  is  practically  impossible  to  do  so 
even  with  classes  of  ten  or  twelve.  Nor  is  it  clear  that  such 
individual  instruction  is  more  necessary  or  desirable  in  connec- 
tion with  the  laboratory  experiments  than  it  is  with  the  experi- 
ments of  the  class  room  or  with  the  illustrations  and  applications 
of  physical  principles  in  daily  life. 


822  SCHOOL  SCIENCE  AND  MATHEMATICS 

It  is  the  business  of  the  elementary  laboratory  to  afford  oppor- 
tunity for  gaining  a  selected  and  directed  experience  under  good 
working  conditions.  It  is  assumed  that  the  pupil  will  endeavor 
to  make  something  out  of  this  experience  at  the  time.  Only  by 
constant  effort  in  this  direction  does  the  work  of  the  laboratory 
become  a  means  of  intellectual  growth.  But  suppose  the  pupil 
fails  of  full  success  in  this  endeavor,  as  he  generally  will.  If 
he  is  one  of  twelve,  he  is  entitled  only  to  seven  and  one  half 
minutes  of  the  teacher's  time  in  a  double  laboratory  period,  and 
to  half  that  in  a  single  period.  His  needs  will  surely  be  better 
served  if  he  has  the  benefit  of  a  class  discussion  in  a  class  of 
twenty  or  more,  even  if  he  must  wait  a  day  or  two  for  this  assist- 
ance. 

If  the  threshing  out  of  results  is  made  the  business  of  the  class 
room,  as  here  advocated,  and  if  the  laboratory  is  fully  in  order 
for  the  work  of  the  hour  before  the  class  assembles,  an  experi- 
enced teacher  can  give  the  necessary  assistance  to  a  class  of 
twenty-four,  or  even  thirty.  Twenty- four  is  the  preferable  max- 
imum ;  for,  as  numbers  increase  beyond  this  limit,  the  details  of 
management  become  more  exacting,  and  the  unavoidable  noise 
and  movement  of  the  class  begin  to  distract  the  attention  and  to 
interfere  rather  seriously  with  the  work.  The  difference  between 
a  class  of  twenty-four  and  one  of  thirty  in  this  respect  is  much 
greater  relatively  than  the  mere  difference  in  numbers. 

The  question  whether  pupils  should  work  singly  or  in  groups 
admits  of  two  satisfactory  answers.  They  should  either  work 
singly  or  in  groups  of  two.  Other  conditions  being  equal,  twice 
as  many  duplicate  sets  of  apparatus  must  be  provided  for  indi- 
vidual work  as  are  required  where  pupils  work  in  pairs.  With 
most  schools  this  consideration  alone  carries  the  decision  in  favor 
of  the  latter  plan;  and  it  has  other  merits.  The  old  adage  that 
two  heads  are  better  than  one  holds  true  in  the  laboratory  as 
elsewhere ;  and  it  is  also  true  that  two  pairs  of  hands  are  better 
than  one  in  many  experiments.  This  plan  requires  more  tactful 
management  than  the  other,  especially  with  large  classes,  since 
a  considerable  amount  of  talking  must  be  permitted,  but  this  is 
not  a  difficult  problem. 

Working  in  groups  of  three  or  more  is  unsatisfactory,  as  a 
rule.  No  more  than  two  can  participate  to  advantage  in  the  use 
of  the  apparatus.  The  others  must  perforce  become  spectators; 
and,  in  the  natural  working  of  the  plan,  this  role  will  fall  to 
the  lot  of  those  to  whom  it  is  most  congenial  but  least  beneficial. 


EXPERIMENTAL  WORK  IN  PHYSICS  823 

The  weaker  members  of  the  group  will  also  depend  upon  the 
more  capable  to  do  the  thinking.  But  worst  of  all,  the  spirit  of 
an  indifferent  member  of  the  group  is  apt  to  prove  contagious. 

To  secure  the  advantage  of  a  minimum  time  interval  between 
the  work  of  the  laboratory  and  the  class  room,  several  duplicate 
sets  of  apparatus  must  be  provided  for  each  experiment.  This 
duplication  has  the  further  important  advantage  of  economizing 
time  in  the  laboratory,  by  saving  the  repetition  of  oral  directions. 
All  things  considered,  the  best  plan  is  to  provide  a  sufficient 
number  of  duplicate  sets  to  accommodate  the  entire  class  on  two 
exercises.  With  pupils  working  in  pairs,  in  classes  of  twenty- 
four  as  a  maximum,  this  would  require  six  sets  of  apparatus 
for- each  experiment.  Twice  this  number  would  be  necessary 
to  accommodate  all  on  the  same  experiment.  The  advantage 
to  be  thus  gained  would  hardly  justify  the  added  expense. 

Double  the  regular  number  of  sets  of  apparatus  should  be  pro- 
vided for  experiments  where  individual  observation  is  necessary 
and  much  time  would  be  wasted  in  taking  turn  at  the  work ;  e.  g., 
in  studying  the  heat  conductivity  of  rods  by  the  sense  of  touch, 
and  in  the  usual  experiments  on  point  image  in  a  plane  mirror, 
the  refraction  of  light  through  plates  and  prisms,  the  study  of 
color,  etc.  It  is  also  a  practical  convenience  to  double  the  regular 
equipment  for  the  first  few  experiments  of  the  course,  in  order 
that  the  whole  class  may  start  together,  and  take  the  experiments 
in  regular  order  from  the  first  day.  The  separation  of  the  class 
into  two  or  more  groups,  as  may  be  desired,  will  soon  take  place 
of  itself,  particularly  where  the  first  exercises  consist  of  several 
short  experiments. 

With  most  schools  an  adequate  equipment  is  a  matter  of  sev- 
eral years'  growth.  In  such  cases  it  is  better  to  begin  by  pro- 
viding two  or  three  or  even  four  sets  of  apparatus  for  each 
experiment  of  a  minimum  course  than  to  provide  only  one  set 
for  perhaps  a  considerably  larger  number  of  experiments.  As 
years  pass,  the  increase  in  the  number  of  experiments  and  in 
the  number  of  sets  of  apparatus  for  each  should  proceed  simul- 
taneously. 

The  importance  of  system,  order,  and  general  fitness  of  condi- 
tions to  the  work  of  the  laboratory  can  hardly  be  overestimated. 
In  such  matters  the  teacher  should  set  an  excellent  example, 
and  he  should  train  his  class  to  follow  it.  Boys  are  notoriously 
careless  and  indifferent  to  the  litter  and  disorder  in  which  they 
may  leave  their  temporary  quarters,  whether  it  be  at  the  labora- 


824  SCHOOL  SCIENCE  AND  MATHEMATICS 

tory  table  or  elsewhere.  The  instincts  and  habits  of  the  cave 
dweller  have  a  strong  hold  upon  them.  As  a  measure  of  self- 
defense,  as  well  as  in  the  interests  of  civilization,  the  teacher 
should  develop  in  his  pupils  a  sense  of  responsibility  for  the  con- 
dition of  the  apparatus  and  table  where  they  are  at  work,  and 
especially  for  the  condition  in  which  these  are  left  at  the  end  of 
the  hour.    The  first  law  of  a  well-conducted  laboratory  is  order. 

Class  Room  Experiments. 

The  class  room  affords  opportunities  for  experimental  work 
of  the  greatest  value  to  the  course.  Without  such  experiments 
the  teaching  is  necessarily  less  effective,  however  fully  the  labora- 
tory course  may  be  developed.  For  various  reasons,  the  experi- 
ments of  the  class  room  are,  as  a  rule,  impracticable  in  the  lab- 
oratory; and  also,  as  a  rule,  they  have  no  laboratory  equivalent. 

The  laboratory  experiment  is  predetermined  and  fixed.  It 
follows  a  set  of  written  or  printed  directions,  from  which  the 
pupil  can  rarely  depart  with  any  profitable  result.  The  class 
room  experiment  is  adaptable.  Where  occasion  demands,  it  can 
T)e  repeated  under  varying  conditions  until  the  essential  facts 
stand  out  clearly;  and  an  experiment,  suggested  by  a  class  dis- 
cussion, can  often  be  improvised  and  tried  out  at  once  to  settle 
a  question  or  a  doubt.  Skill  and  resourcefulness  in  the  adapta- 
tion of  experiments  to  fit  the  questions  of  the  class  add  immensely 
to  the  effectiveness  of  the  teaching;  and  their  exercise  serves  as 
an  impressive  object-lesson  on  the  methods  of  investigation. 

The  experiments  of  the  class  room  are  adaptable  not  only  in 
their  character,  but  in  their  purpose  as  well.  They  fit  into  the 
general  plan  of  the  course  in  a  variety  of  ways.  Most  frequently 
they  serve  to  introduce  new  topics,  particularly  where  the  lab- 
oratory experiments  on  a  topic  are  quantitative.  The  typical 
procedure  in  such  cases  is  as  follows:  (i)  Qualitative  class 
room  experiments,  either  preceding  or  following  an  assigned 
reading  of  the  text.  If  the  reading  precedes  the  experiments, 
the  teacher  will  expect  the  class  to  take  an  active  part  in  an 
informal  discussion  of  them  as  they  are  performed.  If  the  ex- 
periments precede  the  reading,  the  teacher  will  comment  briefly 
upon  them  as  they  are  performed,  directing  the  attention  of 
the  class  to  the  significant  facts  to  be  observed,  and  will  assign 
the  reading  of  the  text  and  the  discussion  of  the  experiments  for 
the  following  day.  (2)  The  laboratory  experiments  on  the  topic, 
supported  by  further  study  of  the  text.     (3)   Recitation  on  the 


EXPERIMENTAL  WORK  IN  PHYSICS  825 

text  and  the  laboratory  experiments,  together  with  problems  and 
applications. 

As  an  example,  let  us  see  how  this  procedure  applies  in  study- 
ing the  reflection  of  light.  Before  the  pupil  begins  the  study 
of  mirror  images  in  the  laboratory,  he  should  have  a  clear  con- 
ception of  beams  and  cones  of  light,  both  diverging  and  converg- 
ing, of  regular  reflection,  of  angles  of  incidence  and  reflection, 
and  of  the  law  of  reflection.  These  ideas  are  readily  grasped 
from  direct  observation  of  beams  and  cones  of  light  in  a  fully 
darkened  room,  into  which  a  horizontal  beam  of  sunlight  is 
thrown  by  a  porte-lumiere.  Chalk  dust  in  the  air  (from  two 
erasers  struck  together)  makes  the  path  of  the  light  plainly  vis- 
ible to  the  entire  class.  The  phenomena  mentioned  are  exhibited 
by  reflecting  the  beam  from  plane  and  curved  mirrors.  Similar 
experiments  can  be  shown  with  the  Hartl  optical  disk  without 
darkening  the  room.  It  is  worth  while  to  use  both  methods. 
Having  this  acquaintance  with  the  fundamental  facts  of  reflec- 
tion, the  pupil  is  better  able  to  work  out  their  consequences  in 
the  laboratory  study  of  mirror  images.  Following  the  labora- 
tory work,  the  class  discussion  or  recitation  is  made  the  occasion 
for  a  general  review  and  summing  up  of  the  topic. 

Not  infrequently  the  experiments  of  the  class  room  are  given 
to  best  advantage  after  the  laboratory  work  on  the  same  topic ; 
e.  g.,  experiments  on  applied  pressure  (Pascal's  law)  after  the 
laboratory  experiments  on  the  gravity  pressure  of  liquids ;  ways 
of  using  the  lever,  following  the  laboratory  exercise  on  moments 
of  force ;  more  detailed  study  of  the  transmission,  absorption, 
and  reflection  of  radiant  energy,  following  the  simpler  laboratory 
work  on  the  same  topic ;  and  similarly  in  the  experimental  study 
of  dispersion  and  color,  magnetism,  electromagnetic  induction, 
etc.  There  is  no  invariable  order  of  class  room  and  laboratory 
work  which  is  best  in  all  cases. 

The  experimental  illustration  of  many  topics  is  best  con- 
ducted wholly  in  the  class  room.  In  such  cases  the  experi- 
ments will  be  presented  from  day  to  day,  coincidently  with 
the  class  discussions  and  recitations  from  the  text.  Among 
the  subjects  which  can  be  presented  to  best  advantage  in 
this  way  may  be  mentioned  the  greater  part  of  dynamics  (the 
mechanics  of  accelerated  motion),  diffusion,  vapor  pressure, 
the  greater  part  of  sound,  and  the  whole  of  electrostatics. 

It  is  clearly  a  misappropriation  of  time  and  energy  to  have 
the  class  keep  a  record  of  the  lecture-table  experiments.     There 


326  SCHOOL  SCIENCE  AND  MATHEMATICS 

is  valuable  training  in  written  work,  when  properly  supervised; 
but  there  is  enough  of  it  and  to  spare  in  connection  with  the 
laboratory  experiments.  To  require  a  written  account  of  the 
lecture-table  experiments,  in  addition  to  the  laboratory  record, 
is  to  exaggerate  this  phase  of  the  work  beyond  all  reasonable 
proportions  and  to  impose  an  intolerable  burden  on  the  class. 

The  equipment  of  apparatus  for  the  class  room  should  be 
entirely  separate  from  that  of  the  laboratory,  and  should  be 
stored,  ready  for  use,  in  an  apparatus  room  directly  behind  the 
demonstration  table.  The  table  itself  should  have  drawers  and 
closet  spaces  of  various  sizes,  for  the  convenient  storing  of 
apparatus  and  supplies  most  frequently  used,  such  as  burners, 
stands  and  supports  of  various  sorts,  glass  and  rubber  tubing, 
tools,  etc. 

A  fairly  complete  equipment  of  apparatus  for  the  lecture  table 
will  cost  from  $800  to  $1,000;  and  $500  will  be  necessary  for 
a  fair  beginning.  It  is  better  to  start  both  the  laboratory  and  the 
class  room  equipment  in  a  modest  way,  and  to  add  to  each  from 
year  to  year,  than  to  expend  all  available  funds  for  either  alone. 

Provision  is  rarely  made  as  it  should  be  for  the  class  room 
experiments  in  light.  Direct  sunlight  is  not  at  all  necessary  in 
the  laboratory,  but  in  the  class  room  it  is  very  important.  One 
side  of  the  class  room  should  have  a  southerly  exposure ;  and 
a  window  near  the  front  of  the  room  on  this  side  should  be 
equipped  with  a  board  shutter,  through  an  opening  in  which  a 
sunbeam  can  be  directed  horizontally  into  the  room,  from  an 
adjustable  porte-lumiere.  The  proper  adjustment  throws  the 
beam  over  and  along  the  lecture  table,  at  a  height  of  ten  or 
twelve  inches,  where  it  can  be  used  for  all  experiments  on  reflec- 
tion, refraction,  dispersion,  and  color.  Sunlight  is  beyond  com- 
parison the  best  and  most  convenient  light  for  the  class  room 
experiments  on  these  topics.  For  most  of  the  experiments  in 
light  the  room  should  be  perfectly  dark.  This  requires  an  opaque 
shade  for  each  window,  in  addition  to  the  ordinary  translucent 
shade.  Both  shades  must  be  wide  enough  to  project  two  or 
three  inches  into  the  deep  grooves  of  a  special  box  window- 
leasing;  and  these  grooves  should  be  painted  black. 


Reprinted  from  School  Science  and  Mathematics,  Vol.  12,  1912. 
Pages  131-137. 

ADAPTATION  OF  PHYSICS  TO  DIFFERENT  TYPES  OF 

PUPILS. 

By  S.  E.  Coleman, 

Head  of  the  Department  of  Science,  Oakland  High  School, 

Oakland,  Cal. 

Need  of  Adaptation. 
One  of  the  chief  obstacles  to  the  best  success  in  the  teaching  of 
physics  is  the  heterogeneous  character  of  the  class.  The  fund  of 
experience,  the  interests,  and  aptitudes,  and  the  present  and  future 
needs  of  the  pupil  are  factors  which  should  largely  determine  the 
matter  and  method  of  the  course ;  and  these  factors,  as  they  apply 
to  the  different  individuals  of  a  typical  physics  class,  are  irrecon- 
cilably different.  To  compromise  differences  on  the  basis  of  the 
"average"  pupil  is  lamentably  unsatisfactory;  for  the  average 
pupil,  so  far  from  being  in  the  majority,  is — like  averages  in  gen- 
eral— a  mathematical  fiction. 

Two  Types  of  Pupils. 

From  the  standpoint  of  physics  as  a  means  of  education,  pupils 
are  of  two  principal  types.  With  those  of  one  type  the  mental 
habit  is  analytical,  logical.  Before  they  reach  high  school  age 
they  have  developed  a  keen  interest  in  the  how  and  the  why  of 
things.  They  have  learned  to  think  in  terms  of  cause  and  effect. 
Even  in  childhood  their  interest  in  what  a  mechanical  toy  does  is 
quickly  subordinated  to  the  desire  to  find  out  how  it  works — with 
consequences  perhaps  disastrous  to  the  toy  but  more  or  less  sat- 
isfying to  the  inquiring  mind.  Thus  from  the  earliest  years 
through  life  this  quality  of  mind  manifests  itself;  it  is  native, 
fundamental.  Pupils  of  this  type  take  to  mathematical  work  with 
comparative  ease.  They  throw  the  burden  where  it  belongs,  not 
on  the  memory  but  on  the  understanding.  They  come  to  physics 
admirably  fitted  for  the  work,  with  a  stock  of  miscellaneous  in- 
formation and  experience  which  is  extensive  and  very  much  to 
the  point,  and  with  interests  and  aptitudes  keyed  to  the  demands 
of  the  subject. 

Pupils  of  the  other  type  are  characterized  negatively  by  the 
absence  or  weakness  of  the  mental  attributes  mentioned.  On  the 
basis  of  this  negative  characterization  alone,  the  type  includes 
the  mentally  inept  or  unfit.  These  do  poorly  in  physics ;  but  they 
are  consistently  poor  in  everything  else  as  well.  But  defect  of 
analytical  and  logical  power  is  very  often  compensated  by  strength 


132  SCHOOL  SCIENCE  AND  MATHEMATICS 

in  other  directions,  as  shown  by  excellence  in  the  languages,  lit- 
erature, history,  art,  and  music.  One  element  of  strength  with 
such  minds  is  a  retentive  memory,  which,  on  occasion,  is  made  a 
substitute  for  reason.  The  inadequacy  of  the  substitution  is  most 
evident  in  the  mathematics  and  in  physics,  where  in  extreme  cases 
it  breaks  down  completely. 

The  above  classification  does  not  divide  the  sexes,  but  it 
does  unmistakably  show  a  sex  difference.  Among  high  school 
pupils  a  very  large  majority  of  the  first  type  are  boys.  The  sec- 
ond type  includes  most  of  the  girls,  together  with  a  considerable 
percentage  of  the  boys.  Whether  the  difference  of  type,  in  so  far 
as  it  is  attributable  to  sex,  is  native  or  acquired  or  partly  both 
is  not  germane  to  the  present  question.  It  is  simply  a  fact  to  be 
reckoned  with  in  education. 

The  Educational  Problem. 

How  best  to  adjust  the  instruction  in  physics  to  the  special 
needs  of  these  two  classes  of  pupils  is  the  problem  demanding 
solution.  It  is  not  solved  by  giving  a  course  adapted  only  to 
the  more  capable  boys,  leaving  it  optional  with  other  pupils  to 
take  the  work  and  get  what  they  can  out  of  it  or  to  decline  it, 
as  they  may  choose.  Neither  is  it  satisfactory  to  adapt  the  work 
to  the  less  capable,  thus  depriving  the  strong  of  that  which  is  for 
them  most  worth  while. 

In  the  small  high  school,  where  there  is  only  one  class  in 
physics,  the  best  that  can  be  done  is  to  supplement  the  class  in- 
struction with  more  or  less  of  individual  help,  the  twofold  pur- 
pose of  the  individual  work  being  to  help  the  weak  over  the 
minimum  requirements  of  the  course,  and  to  provide  extra  work 
for  the  strong  according  to  their  ability.  With  a  very  small  class, 
conditions  approximate  to  the  ideal  in  this  respect,  for  the  in- 
struction can  be  very  largely  individual. 

In  large  high  schools  the  problem  admits  of  various  solutions. 
It  is  solved  as  an  incidental  feature  of  larger  educational  issues 
where  several  high  schools  of  different  types  are  maintained  in 
the  same  city.  The  physics  course  of  the  manual  training  or  the 
technical  high  school  will  naturally  differ  from  that  of  the  Latin 
school  or  a  school  for  girls.  It  is  not  the  purpose  of  the  writer 
to  discuss  the  large  possibilities  afforded  by  such  exceptional  con- 
ditions, but  rather  the  adaptations  which  may  be  made  to  advan- 
tage in  the  undifferentiated  high  school  of  the  large  majority  of 
our  American  cities. 


PHYSICS  TO  DIFFERENT  PUPILS  133 

Adaptation  in  such  schools  usually  takes  the  form  of  a  gen- 
eral year  course,  open  to  all  students,  followed  by  a  more  ad- 
vanced half  year  or  year  course,  intended  primarily  for  those 
who  are  preparing  to  enter  college  or  technical  school.  This 
plan  has  obvious  advantages,  but  at  best  is  only  a  partially  suc- 
cessful compromise.  If  the  work  of  the  first  year  is  reduced  in 
amount  and  adapted  in  character  to  the  less  capable  members 
of  the  class,  it  is  not  of  the  sort  that  should  be  given  to  the 
others.  For  them  the  work  is  an  occasion  for  half  effort  and  a 
discipline  in  the  art  of  loafing.  The  advanced  course  is  a  con- 
fession of  maladjustment,  being  in  the  nature  of  a  supplement 
to  incomplete  work.  If  given  only  for  a  half  year,  it  necessarily 
consists  of  disconnected  fragments,  which  are  only  imperfectly 
articulated  with  the  work  of  the  introductory  course. 

Segregation  of  Pupils. 

The  adequate  adjustment  provides  for  the  segregation  of  the 
pupils  from  the  beginning  of  the  subject.  There  is  much  to  be 
said  in  favor  of  separate  courses  in  physics  for  boys  and  girls. 
This  is  not  a  segregation  according  to  ability  in  the  subject  or 
according  to  mental  type,  but  rather  in  conformity  with  the 
normal  daily  experience,  interests,  and  future  needs  of  the  sexes. 
But  the  educational  values  of  the  subject  are  not  so  largely  in- 
fluenced by  sex  as  to  fully  justify  segregation  on  this  basis  alone. 
Mental  type,  as  above  outlined,  should  largely  determine  the 
scope  and  character  of  the  work  attempted  and  the  methods  of 
instruction.  It  is  a  waste  of  time  to  emphasize  the  mathematical 
side  of  physics  with  pupils  who  have  neither  mathematical  in- 
clination nor  ability,  whether  they  are  boys  or  girls ;  but  such 
work  is  of  great  value  to  boys  who  have  mathematical  ability. 
And  further,  there  are  boys  as  well  as  girls  whose  daily  life 
has  awakened  but  little  curiosity  concerning  physical  matters  in 
general,  and  whose  physical  concepts  are  vague  and  chaotic. 
These  need  the  same  sort  of  help,  regardless  of  sex;  and  the 
boys  would  not  get  this  help  in  a  class  with  capable  fellows. 

The  Oakland  Plan. 
Giving  due  weight  to  all  elements  of  the  problem,  the  best 
solution  apparently  is  to  offer  two  parallel  courses  in  physics, 
differing  largely  in  method  and  in  the  amount  and  character  of 
the  subject-matter,  but  open  to  both  sexes.  This  plan  has  been 
followed  for  some  years  in  the  Oakland  High   School,  and  it 


134  SCHOOL  SCIENCE  AND  MATHEMATICS 

works  well.  The  two  courses  are  designated  respectively  as 
full  and  brief  physics.  The  full  course  is  intended  primarily 
for  the  more  capable  boys,  and  is  taken  by  all  who  need  physics 
for  their  work  m  college  or  technical  school.  With  a  selected 
class  of  pupils,  the  work  is  more  vigorous  and  thorough  than 
is  ordinarily  possible.  The  mathematical  side  of  the  work  is 
emphasized,  and  includes  incidental  instruction,  as  occasion  de- 
mands, in  the  sensible  use  of  mathematics  as  a  tool.  Much  at- 
tention is  given  to  the  practical  applications  of  physics  in  daily 
life.  The  brief  course  dwells  at  greater  length  on  the  qualitative 
aspects  of  phenomena,  omits  much  of  the  usual  mathematics  of 
the  subject,  reduces  and  simplifies  the  work  in  mechanics,  takes 
fewer  quantitative  laboratory  experiments,  devotes  less  time  to 
practical  applications.  Astronomical  topics  are  introduced  here 
and  there,  as  they  fit  into  the  regular  order  of  the  work.  Thus 
in  dynamics,  the  motion  of  the  earth  and  planets  round  the  sun 
and  of  the  moon  round  the  earth,  the  bulging  of  the  earth  in 
equatorial  regions  due  to  rotation,  the  apparent  diurnal  motion 
of  the  starry  heavens  explained  as  the  result  of  the  earth's  ro- 
tation, and  the  apparent  seasonal  motion  as  the  result  of  the 
earth's  revolution  round  the  sun  (based  on  observation  of  the 
brightest  stars  and  some  of  the  principal  constellations),  nature 
of  the  sun  and  stars  as  distinguished  from  the  planets,  relation 
of  the  solar  system  to  the  stellar  universe.  In  heat,  the  inclina- 
tion of  the  earth's  axis,  varying  length  of  day  and  night,  cause 
of  the  seasons,  source  of  the  sun's  heat,  solar  energy  as  the 
cause  of  terrestrial  phenomena  (winds,  rain,  plant  growth,  etc.), 
physical  conditions  on  the  moon  and  Mars.  In  light,  eclipses 
of  the  sun  and  moon,  phases  of  the  moon,  the  solar  spectrum 
and  its  teachings. 

The  full  course  presupposes  ability,  aptitude,  and  adequate 
preparation  for  the  subject.  A  good  record  in  mathematics  is 
regarded  as  evidence  of  fitness  for  the  work.  Although  chem- 
istry is  not  made  a  prerequisite,  it  rarely  happens  that  any  mem- 
ber of  the  class  has  not  taken  the  subject.  The  full  course  thus 
fits  in  with  a  high  school  education  which  is  somewhat  special- 
ized along  mathematical  and  scientific  lines. 

The  aim  of  the  brief  course  is  the  general  educational  aim. 
It  presupposes  no  specialization  and  looks  forward  to  none.  It 
purports  to  deal  with  matters  of  general  interest  and  importance, 
and  welcomes  students  whose  intelligence  and  general  training 
are  such  as  may  reasonably  be  expected  of  all  third  and  fourth 


PHYSICS  TO  DIFFERENT  PUPILS  135 

year  students  in  the  high  school.  The  only  specific  requirement 
is  a  certain  minimum  of  algebra  and  geometry.  As  regards  the 
content  of  the  course,  it  is  certain  that  all  girls  and  many  boys 
are  more  interested  in  learning  something  of  the  orderly  plan 
and  meaning  of  the  universe  at  large  than  they  are  in  learning 
details  about  hydraulic  presses,  steam  pumps,  steam  engines, 
dynamos,  etc.  The  brief  studies  in  astronomy  above  outlined 
never  fail  to  arouse  the  deepest  interest,  which  reacts  to  the 
benefit  of  the  more  prosaic  side  of  the  work.  It  should  not  be 
overlooked  that  this  astronomy  is  also  applied  physics,  serving 
admirably  to  illustrate  the  laws  and  principles  of  the  subject, 
and  that,  as  information  tending  to  broaden  the  mind  and  to 
enlarge  one's  outlook  upon  life,  it  is  worth  more  than  much  of 
the  practical  physics  that  we  are  at  present  so  intent  upon 
bringing  into  the  high  school  course. 

Time  and  Credit. 

The  two  courses  are  given  the  same  amount  of  time  on  the 
school  program,  and  each  is  completed  in  one  year;  but  the  full 
course  demands  more  time  on  the  outside,  and  ranks  as  a  course 
and  a  half  toward  graduation.  The  work  would  be  extended 
over  a  year  and  a'  half  if  circumstances  permitted.1 

Pupils  in  the  Brief  Course. 

.  The  choice  of  the  girls  is  the  brief  course,  almost  without 
exception.  It  is  preferred  even  by  those  who  are  fully  compe- 
tent to  take  the  other,  because  the  subject-matter  and  the  less 
intensive  treatment  are  more  to  their  liking.  It  is  taken  by  a 
considerable  number  of  the  boys  for  the  same  reason,  and  not 
infrequently  for  the  further  reason  that  they  have  neither  the 
training  nor  the  ability  demanded  by  the  full  course. 

A  Suggestion. 

It  is  not  essential  to  the  plan  and  purpose  of  the  brief  course 
that  it  should  include  the  astronomy  outlined  above,  or  any 
part  of  it.  Although  very  much  worth  while,  there  is  an  abun- 
dance of  good  material  that  may  take  its  place.  Elementary 
meteorology  is  simple  applied  physics,  is  of  general  interest, 
and   serves   admirably   to   illustrate   many   topics   in   mechanics 


*Since  this  article  was  offered  for  publication,  our  school  program  has  been  arranged 
to  give  7  periods  per  week  during  the  first  half  year  and  8  periods  per  week  during  the 
second  half  year  to  the  full  course.  The  time  allotted  to  the  brief  course  remains,  as 
before,  5  periods  per  week  through  one  year. 


136  SCHOOL  SCIENCE  AND  MATHEMATICS 

and  heat.  This  material  will  be  found  fully  worked  out  in  any 
elementary  text-book  of  physical  geography.  Of  like  utility 
are  such  topics  as  the  heating  and  ventilation  of  buildings,  the 
fireless  cooker,  the  use  and  dangers  of  volatile,  inflammable  liq- 
uids (gasoline,  kerosene,  alcohol),  including  tests  of  flashing 
point  and  burning  point,  artificial  illumination,  electricity  in 
the  home,  etc. 

A  Rational  Solution  of  Disputed  Questions. 

The  differentiation  of  elementary  physics  into  two  parallel 
courses  affords  the  only  rational  solution  of  certain  questions  on 
which  there  has  long  been  an  irreconcilable  difference  of  opin- 
ion among  physics  teachers.  Should  the  quantitative  side  of 
physics  be  brought  out  strongly,  with  quantitative  experiments, 
derivation  of  formulas,  solution  of  numerical  problems,  etc.? 
Yes,  in  the  full  course;  in  the  brief,  no. 

If  any  class  of  students  can  derive  reasonable  benefit  from  the 
present  mathematical  courses  of  the  high  school,  then  the  same 
class  of  students  can  derive  equal  or  greater  benefit  from  the 
mathematical  work  of  the  physics  course.  If  it  is  profitable  to 
study  pure  mathematics,  it  is  no  less  profitable  to  put  a  mod- 
icum of  the  knowledge  gained  to  the  test  of  practical  use;  and 
physics  offers  almost  the  only  opportunity  in  the  high  school 
for  such  use.  The  objection  that  mathematical  physics  is  too 
hard  is  met  by  the  answer  that  it  is  not  so  hard  as  much  of  the 
pure  mathematics  that  the  student  has  already  taken — or  en- 
dured. The  objection  that  it  is  uninteresting  is  met  by  the  same 
answer,  with  the  advantage  again  in  favor  of  physics,  for  the 
problems  of  physics  have  a  more  significant  content.  It  should 
be  admitted,  however,  that  the  argument  is  valid  against  both 
the  mathematical  physics  and  the  traditional  courses  in  algebra 
and  geometry,  for  a  large  percentage  of  high  school  pupils. 
The  physics  teacher,  when  charged  with  inhumanity,  should  not 
attempt  to  justify  himself  by  replying,  Tu  quo  que.  He  should 
give  the  mathematical  work  in  good  measure  to  those  who  can 
profit  by  it,  with  full  assurance  that  it  is  worth  while,  and  should 
reduce  it  to  a  harmless  and,  let  us  hope,  profitable  minimum  for 
the  others. 

The  question  as  to  the  proper  treatment  of  kinetics  (the  be- 
havior of  matter  undergoing  acceleration)  finds  a  similar  an- 
swer. With  a  selected  class  of  boys,  it  should  be  possible  and 
profitable  to  treat  the  subject  quantitatively,  in  terms  of  both 
the  gravitational  and  the  absolute  units  of  force;  but  with  girls 


MOMENTUM  BALANCE  137 

generally  and  with  many  boys  there  is  little  profit  in  elaborat- 
ing the  quantitative  relations.  The  choice  of  suitable  illustrative 
material  (practical  applications,  etc.)  also  becomes  a  compara- 
tively simple  matter,  as  already  noted. 

Discriminating  Use  of  the  Text-Book. 
In  the  light  of  the  foregoing  discussion,  it  is  clear  that  the  use 
of  the  text-book  calls  for  discrimination  on  the  part  of  the 
teacher.  It  is  the  teacher's  privilege  to  select  and  reject  ac- 
cording to  his  own  best  judgment.  If  the  contents  of  the  text 
are  well  ordered,  so  that  essentials  can  be  taken  and  non-essen- 
tials omitted  without  break  in  the  general  plan  and  continuity 
of  the  subject,  then  an  overplus  of  material  becomes  a  valuable 
feature  of  the  book;  for  it  affords  opportunity  for  choice,  and 
its  presence  invites  attention  and  stimulates  interest. 


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